Adjust External Display Size

When I use my MBP on my 50 inch Panasonic 720p TV the screen size is slightly larger than the TV display. ie the the top status bar and the sides are cropped from view on the TV. The display setting in MBP are at 720p.

If there anyway to adjust the display size on the MBP. I am a previous windows user and with windows there is always an option under TV option to increase and decrease aspect ratio.

Any help will be great. Thanks.

 

Where can I find the over and underscan options...I don't see it anywhere under system preferences-->display